Thanks for the info! That makes a lot of sense... However is there a stiffer plastic tubing that is also used often? What I am seeing on my kites looks closer to a shiny black vinyl material, similar to end caps. Although, I guess it could also be that as the heat shrink tubing shrinks in size it also gets glossy, thickens up and stiffens looking more like vinyl?... Sent from my iPhone using KiteLife mobile app